Dobbie mechanism



Dec. 31, 1963 T. HINDLE 3,115,899

DOBBIE MECHANISM Filed Feb. 17, 1961 I 4 Shets-She'et 1 INVENTOR '1' Wm! lla'izdle BY a... QQM v ATTORNEY Dec. 31, 1963 T. HINDLE 3,115,899

v DOBBI'E MECHANISM Filed Feb. 17, 1961 4 Sheets-Sheet 2 0 W 55 w; M 0

INVENTOR mm; 12971416 z ml a ATTORNEY Dec. 31, 1963 Filed Feb. 17, 1961 T. HlNDLE DOBBIE MECHANISM 4 Sheets-Sheet 4 F/6; 7 .4 ya N h INVENTOR.

mar/aw HIM/8 United States Patent 3,115,899 BOBBIE MECHANISM Thomas Hindle, Thornlea, Beardwood Brow, Blackburn, England Filed Feb. 17, 1961, Set. No.9t),063 Claims priority, application Great Britain Feb. 20, 1960 23 Claims. (Cl. 13976) This invention relates to dobbies for weaving looms, used principally for operating the heald shafts of a loom but, as explained below, useful also for some other purposes. The invention relates to dobbies of the type (be ing the type referred to in the appended claims) including a plurality of continuously-rotating segment-gears adapted independently to engage and dis-engage a corresponding number of crank-gears which, by their consequent intermittent half rotations, actuate jack-levers by which the dobby carries out its functions, e.g. the heald-frames of the loom are lifted and lowered through the medium of streamer connections, pulleys and tie-ups. In this known type of dobby, the intermittent engagement of the segmentgears and crank-gears has taken place under the control of a pattern chain in which the desired sequence of gear and jack movements is recorded for serial operation.

Said type of dobby, known principally as a Leeming positive open-shed dobby or loom head-motion, has the said segment-gears slidably mounted on splined driving shafts, usually two in number, which are geared together and driven at loom crankshaft speed. Each segmentgear is individually controlled (as to its lateral position on the splined shaft) by the pattern chain, which chain is built up in the usual manner from bowls and tubes, and act on the segment-gear through a cam-lever. When a cam-lever is :lifted by a bowl on the pattern chain, it causes its associated rotating segment-gear to be shifted laterally along its splined shaft into the engage position, in which the teeth of the gear, at the appropriate time in each revolution, engage the teeth of the mating crankgear and rotate the latter a half-turn. During such halfturn rotation of the crank-gear, the corresponding heald jack-lever is positively swung about its fulcrum from one extreme position to the other by means of a connecting rod which links it to a crank pin fixed to the crank-gear.

If, for explanatory purposes, it is assumed that a healdframe is down, then the above-described actuation of the jack-lever, due to a bowl on the pattern-chain having operated the cam-lever, would lift the heald-frame to its top position. On the other hand, if the heald-frame is up, the described actuation would lower it to its bottom position.

Furthermore, if the next step of the pattern-chain presents a second bowl to the same cam lever, such lever is maintained in its raised position and the corresponding segment-gear remains in its lateral engage position. The consequent further half-turn rotation of the crankgear then actuates the jack-lever in the reverse direction and, on the assumption that the heald-frame is up, lowers it to its down position and vice versa. On the other hand, if the said second step of the pattern-chain instead of presenting a second bowl presents a tube to the cam-lever then that lever, previously raised by a bowl in the preceding step of the chain, is now free to descend under the action of gravity or a spring, with the effect that the segment-gear is shifted back laterally along its splined shaft into the miss position, in which it is free to revolve indefinitely, without engaging and rotating its crankgear, so long as the pattern-chain presents a succession of tubes to the cam-lever. Conversely, the presentation of a succession of bowls to the cam lever in consecutive steps of the chain returns the corresponding segment-gear in its engage position and causes successive changes in the 3,115,899 Patented Dec. 31, 1963 jack positions, one for each step of the chain, in which case the heald-frame is alternately lifted and lowered. It follows, therefore, that the pattern-chain for use with the known form of Leeming dobby must be pegged for changes, in consequence of which the make-up or pegging is quite different from the weaving or lifting plan. This is in striking contra-distinction to the more usual and generally preferred method of pegging for risers and fallers associated with other types of dobby in general use.

With a Leeming pattern-chain, specially prepared on the pegging for changes system as described, it is furthermore essential, before commencing weaving first to marshal-l all the heald-frames into their correct up and down positions to correspond with a selected starting position of the pattern-chain. Knownforms of Leeming dobby are provided for this particular purpose with a series of special hand levers, one for each jack and heald frame, and the heald frames have to be manipulated into their appropriate starting positions by turning a hand wheel which actuates the dobby mechanism separately from the loom crankshaft. Nevertheless, the mechanical principle involved in the intermittently engaging segmentgears and their mating crank-gears in a dobby of the type referred to offers outstanding advantages because of the positive driving action and reversibility of the gears, which properties enable a loom complete with dobby to be temporarily driven in the backward direction Without any need for the special clutches and reversing bevel-gears essential with other known dobby mechanisms.

The possibility of running the loom, including the dobby, backwardly is of a special importance when Weaving the extremely wide felts for use on paper-machines. Weaving faults in such felts are not permissible since the presence of such faults in the felt would produce defects in the paper. However, it occasionally happens that a faulty shot of filling is inserted into the cloth and before the weaver notices this faulty shot, several more shots of filling may be inserted. Under such circumstances, it is necessary first to remove the latter shots of filling, one at a time, and then when the faulty filling is reached to remove that, after which normal weaving may be resumed.

To facilitate such a procedure, when necessary, the loom motor is made reversible so enabling the loom crankshaft and the dobby, driven therefrom, to be run backwards, that is to say, reversed one revolution at a time from one open shed to the next. During these successive operations, the pattern chain also turns backwards and therefore controls the shedding in the reverse order and each time the loom is stopped with the shed open, a shot of filling can be pulled out. This unweaving process is continued until the faulty filling has been reached and removed from the cloth, after which the normal weaving is resumed with the motor, the loom crankshaft, the dobby and the pattern-chain all turning in their normal or forward direction. Since the cloth take-up rolls are driven from the crankshaft they turn backwardly when the loom, as a whole, is temporarily reversed thus maintaining the fell of the cloth at the normal position. Mechanism is available, for example such as is disclosed in the copending application of Thomas I-lindle et al., Serial No. 97,127, filed February 23, 1961, for turning the warp beam backwardly so as to take-up the warp yarn resulting from the unweaving. It may be noted that during such unweaving process the shuttle-picking motion is put out of action temporarily.

The object of the present invention is to provide an improved arrangement of the dobby of the type referred to, which is capable of reliable operation in connection with wide and heavy looms such as are required for weaving paper-machine felts, where such greater stresses are involved than in an ordinary loom, and which is responsive to a pattern record set for risers and fallers instead of for changes.

According to this invention, a dobby of the type referred to is characterised by a pattern record adapted to be sensed serially by a sensing means which, in dependence on the pattern signals sensed, puts a jack-operating mechanism into active condition so that it moves the jack to its then opposite position, and by feeler means which in response to such movement of the jack causes said jack-operating mechanism to be out of active condition again when the jack movement is completed, ready for the next operation of the sensing means. In normal cases, the pattern record will be a pegged pattern chain or a chain built up from bowls and tubes in known manner and the sensing means a series of finger levers which rise and fall in dependence on th epresence or absence of the pegging, or in dependence on the presentation of a bowl or tube rsepectively to each finger lever. In some other cases, a perforated tape, magnetic tape or magnetic drum may be used as the pattern record, with sensing means appropriate thereto.

According to another feature of the invention, for each jack lever, the said sensing means and feeler means are interconnected by a floating lever which controls a servo device for the jack-operating mechanism in such manner that, when the combined effects of the sensing and feeler means give such floating lever a particular attitude (or any one of a number of predetermined attitudes), the servo mechanism is brought into operation to shift the jack, and in such manner also that the consequent operation of the servo mechanism results in the floating lever adopting another attitude in which the servo mechanism is rendered inoperative.

It is also proposed according to the invention, in a dobby having upper and lower banks of segment gears, to pivot the cam levers for the upper bank of gears on one shaft and those for the lower bank of gears on another shaft, with a finger lever, floating lever and feeler lever combination for each upper cam lever and a similar combination for each lower cam lever, and to arrange upper and lower servo mechanisms for the respective upper and lower gears as parts of a mechanical relay, wherein, when the floating lever of any such combination is in a certain attitude or condition, the corresponding servo mechanism is made inoperative on the jack lever concerned, whilst such floating lever, when in either of two other attitudes or conditions, makes the corresponding servo mechanism operative, every moment of a jack by a servo mechanism bringing the floating lever for that jack back to its servoinoperative attitude.

In a modification of the invention, instead of a wholly mechanical arrangement, an electro-mechanical relay arrangement is employed in which the pattern record sens ing means and the feeler means operate electric switches in circuits controlling the servo mechanisms. In such an arrangement, if for any jack, corresponding switches operated by the sensing means and the feeler means respectively are both closed in the same one of two circuits, a jack movement follows and one of the switches opens again, whereas if the switches are closed one in each of said circuits, no jack movement follows.

It is an important advantage of this invention that once a jack-changing movement has begun, say because of the above-mentioned mechanical relay or electro-mechanical relay arrangement having been set for operation, the relay becomes automatically held or stored until after the jackchanging movement has been completed. Thereby, any stoppage of the loom or failure of current in the electromechanical devices during the changing of the jack and/ or after the pattern chain has been notched forward, does not cancel out the change; the change intended remains in control of the mechanisms and, in the first-named even- 4 tuality the change is completed as soon as the loom is re-started, whilst in the case of a cun'ent failure the change continues without interruption. This storing of an intended change may be effected, for example, by having in said servo-mechanisms interlocking formations on the mutually-engaging parts of, on the one hand, constantly-driven lifting members and, on the other hand, push rods movable into and out of the path of the lifting members by the said relay.

According to this invention also, means is provided in a dobby for levelling all the heald frames in either their topmost positions or their centre-shed positions, each of these alternatives being instantly available in entirely free choice to the weaver, and the said means allowing of rapid return of the levelled heald frames to the position occupied immediately before levelling.

The invention will now be described with reference to the accompanying drawings, wherein:

FIG. 1 is an elevation, omitting the dobby framing, showing the arrangement and principal mechanism of the improved dobby, including the mechanical relay or servo mechanism which, in this form of the invention, is responsive to the normal-type pattern-chain through the automatic selective action of a floating-lever and asso ciated mechanical linkage;

FIG. la is a fragmentary edge elevation of the gearshifting elements;

FIG. 1b is a fragmentary sectional view showing the engageable portions of a motion-transmitting dog and lifter bar;

FIG. 2 shows in diagrammatic outline the driving mechanism for actuating the mechanical relay or servo mechanism;

FIG. 3 is a timing diagram, related to the loom crankshaft, showing the operation of the mechanical relay and associated parts, which timing is identical for both directions of rotation;

FIG. 4 is a diagram illustrating the automatic selective action of the floating-lever and its associated mechanical linkage;

FIG. 5 is an elevation corresponding to PEG. 1, show ing an arrangement in which the mechanical relay or servo mechanism is responsive to the normal-type pattern-chain through the automatic selective action of a particular arrangement of electric switches acting in combination to control electro-magnets or solenoids which in turn activate the mechanical relay;

'FIG. 6 is a section to larger scale, in the vertical plane of the shafts on which the driving and driven gears are mounted, showing the gear-shifting lever in its down position;

FIG. 6a is a similar view but showing the drive gear as having turned 180;

FIG. 7 is a similar view showing the shifting lever in its upper position;

FIG. 7a is a similar view but showing the driven gear as having turned and FIG. 8 is a fragmentary elevation, to larger scale than IG. 2, showing the relay cam and the parts actuated thereby.

Referring to FIG. 1, 1 and 2 are two of a plurality of vertical jack-levers adapted to swing on their common fulcrum-pin 3, whereby they lift and lower the healdframes (not shown) through horizontal top and bottom pull-rods (not shown) flexibly attached to the extreme ends of the jack-levers at 4 and 5 respectively. In the drawing the top left hand position of the jacks represents the down position of the healds and the top right hand represents the up position.

The mechanism includes upper and lower banks of segmental gears, each with its associated crank gears. Alternate jacks are operated from the top bank of gears, and the intermediate jacks from the bottom bank. Considering the top bank gears, the connecting-rod 6 connects the pin 8 fixed in jack-lever 1 to the crank pin it) fixed in crank-gear 12. Each crank-gear in the upper bank rotates on its own axle-pin 12a, fixed in spider 14-, the several spiders of the upper bank being supported on and clamped to through-bars 16, 16, both ends of which are rigidly supported to the dobby frames.

Segment-gear 26 is one of a number of constantly rotating gears slidably mounted on the splined shaft 18, which shaft is geared to and rotates at the same speed as the loom crankshaft. The shifter 22, which effects lateral movement of the segment-gear and is restrained from rotating together with its associated segment-gear 2% by the floating register bar 22a, fits into a groove formed in the boss of segment-gear 20, and is also provided with two diametrically-opposite pins 26 which are in two camgrooves 24 machined in the calm-lever 28.

These cam-grooves 24, the general form of which is shown at C in FIG. 1a, are so shaped that as the camlever 28 is raised, meanwhile swinging on its fulcrum-pin 30, the shifter 22, and its associated rotating segmentgear 2! is shifted laterally for an appropriate distance along splined shaft 18 into the engage position where its teeth will mesh with the teeth of the crank-gear 12. Conversely, when the cam-lever 28 is allowed to descend, under the action of gravity and/or a spring, to its inert position in which lug 32 acts as a stop by resting on spacing-bar 34, the shifter 22 and its associated rotating segment-gear are shifted back again aiong shaft 18 to the miss position where the teeth of the constantly rotating segment-gear are unable to mesh with those of the crankgear.

Thus, when the cam-lever 28 is raised the requisite distance (which depends upon the shape of cam C), the teeth of the segment-gear 26 come into alignment with and in due course engage the teeth on one-half of the mating cranlogear 12, thereby rotating it a half-turn. During such half turn, the crank-pin It causes the connecting-rod 6 to swing jack-lever 1 to the right about its fulcrum-pin 3, so as to lift the associated heald-frame. Upon completion of each such half-turn, the crank-gear is held stationary, with the crank-pin on either dead centre, by the concave projection 37 of that gear being engaged by the arcuate ridge 36 formed on the segmentgear (between the ends of the toothed portion) and also on the contiguous periphery of shifter 22.

As shown in PEG. 6 the gear-shifting lever 23 is in the down position and consequently the part 22 has been moved to the right where its untoothed arcuate edge engages with and locks the upper untoothed segment of the crank gear 12. In this lateral position the drive gear 24? may rotate with the shaft 18 without driving the crank gear. This is indicated in FIG. 6a in which the teeth of the drive gear 2% are shown as out-of-mesh with the teeth on the crank gear 12.

In FIG. 7 the lever 23 is shown in its upper or raised position in which the shifter 22 has been displaced to the left so that the untoothed edge of the drive gear 24 locks the crank gear 12 until, at a later point in the cycle, the teeth of the drive gear 12 mesh with the teeth of the crank gear so as to turn the latter through an arc of 180. The relative positions of the drive gear 20 and the crank gear 12, after the latter has turned through an angle of 90", is illustrated in FIG. 7a.

'In a corresponding manner jack-lever 2 is adapted for actuation by crank-gear 13 in the bottom bank of gears. Thus, half the jack-levers are actuated by the top bank and the other half by the bottom bank of crank-gears. The division of the jack-actuating gears into two banks in this general manner is one of the outstanding features of the Leeming dobby. For any specified pitch of healdframe operation, the permissible thickness or width of the individual gears may be increased two-fold by such division, and this is particularly advantageous in the case of very heavily-loaded dobbies intended for use on heavy and wide looms such as are required for weaving paper machine felts.

In such wide looms, however, it is not practicable to derive the differential he-ald travels, required to conform to the shed angle, by anchoring the various pull-rods or streamers at progressively increasing radii on the jacklevers, as is common practice on looms of ordinary width, and which is primarily founded on the crank-pins 10 having the same radius of throw on all crank-gears. In wide looms of the class referred to, which may attain a weaving Width of 8 0 -feet or more, the pull-rods must necessarily extend horizontally above and below and longitudinally of their respective heald-frames, with frequent tie-ups and associated pulleys along the full width of the loom for connecting the heald-frames to such top and bottom pull-rods.

Accepting the necessity to anchor all the pull-rods to the jack-levers at one and the same radius from the fulcrum pin 3, that is, at the extreme ends 4 and 5, of the vertical jack-levers 1 and 2 shown in FIGS. 1 and 5, the required progressively graded lift or travel of the healdframes from front to back is achieved by progressively increasing the effective radius (or throw) of the crankpins it on the crank-gears corresponding to the front to back positions of the heald-frames.

In the known Leeming dobby construction, the two banks of cam-levers corresponding to the levers 28 and 2 in FIG. 1, have a common fulcrum-pin and are directly actuated by the bowls and tubes of the pattern-chain, which, as already explain-ed, must be pegged for changes.

In the illustrated embodiments of the present invention, each bank of cam-levers .28 and 2d has its separate fulcrum at as and 31 respectively, and the cam-levers are adapted to be raised (as and when required to rotate the crank-gears a half-turn) by a mechanical relay or servo device which is itself responsive to a pattern record (as shown a pattern chain) pegged for risers and fallers.

In the embodiment shown in FIG. 1, this mechanical relay or servo-means comprises (with reference to the top bank of cam levers and for each respective cam lever), a push-rod, dog, or trip-member, here shown as a bellcran k lever having the long, downwardly directed arm 38 and a relatively short, horizontal arm, such a dog or tripmember being pivotally connected as at 44! to each corresponding cam lever 2-8. With reference to the bottom bank of cam levers 29, a similar push-rod, dog or tripmem'cer, having the long, downwardly directed arm 39, is pivotally connected at 4th to each corresponding cam lever 29. These dogs or trip-members are adapted to be engaged, or not, by the power-driven, vertically reciprocating drivers or lift bars 4-4 and 45 respectively. Normally, the long, downwardly directed arm 58 of the push-rod or dog of the upper bank is held clear of the path of movement of the driver or lifter 4 4 by a spring 4 2 acting on the short, substantially horizontal arm of the dog. A similar spring 43, acting on the horizontal arm of the dog of the lower bank having the long arm 39, normally holds the latter arm out of the path of the lifter 45.

As shown, by way of example, at the lower part of FIG. 1, the dog having the arm 39 has been swung over to the left until the lower end of the arm 39 is in the path of the vertically moving lifter 45 and will be engaged by the latter and positively lifted as the lifter moves upwardly from the position shown in FIG. 1, to the extent necessary to raise the cam lever 29 and thus shift the drive gear 2i so that its teeth may engage teeth of the crankge-ar, it being noted that so long as the lever 29 remains in this position the crank-gear will continue to turn onehalf revolution for each rotation of the shaft 19.

Referring now to FIG. 2, the two lifting-bars 44 and 45, suitably guided in vertical slots in the dobby frames (not shown), move up and down in unison under the action of a constantly turning relay cam 76 keyed to shaft '75, which is driven in time with the loom crankshaft. The train of spur-gears 77 serves to connect the shafts 18, 19 and 75' so that all of them rotate constantly at loom crankshaft speed. As shown in FIG. 2, the lifting-bars and their actuating levers and linkage descend due merely to their own weight, but in some cases return springs (not here shown) may be employed to assist their descent, or a positive cam may be used at 76 in place of the negative or edge cam shown. As diagrammatically illustrated in FIG. 2, a bell-crank lever 73, pivoted at 78m has, at the end of one arm, a cam-follower roll 73b which consantly engages the peripheral edge at relay cam 76. The other arm of lever 78 is connected b a link 79 to the lifter-bar 44-. A second link 7% connects the last-named arm of the bell-crank lever '78 to a lever 73a which, in turn, is connected to lifter-bar 45 by a link 79x.

Referring to FIG. 8, wherein the so called relay cam 76 is shown to larger scale than in FIG. 2, it will be noted that this cam is symmetrical with respect to the diameter indicated by the line XY and in consequence the rotation of this cam in either direction will produce exactly the same motion of the lifting-bars 4- and 45 diagrammatically indicated in FIG. 2.

The preferred timing of the relay cam 7-6 is shown by FIG. 3, in which the arrow F indicates the normal or forward direction of rotation of the loom crankshaft, and the arrow R the reverse direction. PC marks the frontcenter position of the crank, BC the back-center position. The angle 1--2 is that which is devoted to moving the healds; the angle 21 is that which is devoted to the dwell of the heald in the up position; the angle 23 is devoted to the downward motion of the lifting-bars 44, 45; the angle 34 is devoted to the stepping along of the pattern-chain; and angle 4l is devoted to the ascent of the lifting-bars id, '45. Thus, the same timing of events applies to either direction of rotation, the sequence being symmetrical about the horizontal line FC, BC (FIG. 3). This symmetry allows of the dobby operating with equal efliciency in either direction of rotation of the loom crankshaft.

The sequence of operations resultant from the turning of this cam in the forward direction is as follows: (1) the downward motion of the lifting bar 44; (2) the stepping forward of the pattern-chain P; (3) the upward motion of the lifting-bar 4-4; and (4) the shedding or change of headle position by one of the levers 1 or 2.

It should be noted that in the above sequence of motions the dwell of the headles in the open-shed position proceeds concurrently with the above steps 1, 2 and 3, and occupies approximately 180 of the crankshaft revolution, while the shedding or change of headle position, that is to say, the fourth of the above steps, occupies the remaining 180. It may be assumed that the line X-Y of FIG. 8 represents a line passing through the front and back dead centers of the loom crankshaft as just above suggested, and if the crankshaft be reversed the sequence of operations is exactly the same as above described, that is to say, l) the lifter-bar 44- will be moved downwardly; (2) the pattern-chain will be stepped backwardly; (3) the lifting-bar will move upwardly; and (4) the shedding or headle positioning takes place. As indicated in FIG. 8, rotation of the cam '77 in a counterclockwise direction, that is to say, the forward direction, from the position in which the arrows T are directly opposed to each other and in which the arrows D and D are likewise opposed to each other will, at the end of a half-revolution of the cam, have brought the arrow D into direct opposition to the arrow K, where it will dwell while the cam makes something more than a half-revolution whereupon the arrow D will again be carried down until it is directly opposed to the arrow D Rotation of the cam in the opposite direction will produce exactly the same result.

When the arrows T are opposed to each other, as shown in full lines, which is the back-center position, rotation in either direction will move the arrow -D up until it is opposed to the arrow K, which represents upward movement of the lifting-bar. This motion is completed just as the cam-follower roll reaches the commencement of the long dwell F of the cam, but when the cam-follower 0 roll reaches the end of this dwell, the arrow D will immediately begin to move down toward arrow D thus lowering the lifter-bar. :It is during the time when the arrows T are nearly in opposition that the pattern-chain moves forwardly.

Referring again to FIG. 1, the jack feeler-levers or control elements .6 and d7 are respectively associated with jack-levers 1 and 2. They are free to swing on their common fulcrum-pin 72, turning clockwise around the pivot under the action of gravity and rising or turning counterclockwise in response to force applied by rollers 48 and d9 fixed to and moving with the jack-levers. When, for example, jack-lever 2, was last moved to the position shown in FIG. 1, thereby lifting its heald-frame, the roller 4-9, which is in continuous engagement with the cam profile '74, allowed the horizontal or long arm of feeler-lever 47 to fall by its own weight to the position shown in FIG. 1. in the course of this movement the free end of the long arm of each jack feeler-lever or control element descends from a position such as indicated at "0 (FIG. 1) to a position such as indicated at 51 (FIG. '1). When the free end of the long arm of a control element occupies the position 50, the corresponding heald-frame is down and when the free end of the long arm of a control element occupies the position 51, the corresponding heald-frarne is up.

To the free end of the long arm of each control element (for example, the arms 46, 47, FIG. 1), there is hinged the inner end of a corresponding floating lever F, hereinafter, at times, referred to as a determinator.

The opposite or outer end of each floating lever or determinator F is connected by a link 61 to a corresponding finger-lever or pattern-follower 57 to which the link is pivoted at 59. All of the finger-levers or pattern-followers 57 are mounted upon a common fulcrum bar 53. A single pattern device P suflices for both banks of gearshifting or cam levers. This pattern device P, as here shown, comprises an endless chain 6% carrying pattern indications or signal elements of two distinct types, herein referred to, respectively, as bowls B and tubes T. A bowl B, when in operative relation to one of the fingerlevers or pattern-followers 57, calls for a lifting of the corresponding heald-frame while a tube T, when in opera tive relation to the finger-lever or pattern-follower 57, calls for a lowering of the respective heald-frarne. When resting on a tube T of the pattern device, as illustrated in FIG. 1, the pattern-follower 57 allows that end of the floating lever or determinator F, which is connected to the link 67 to descend (preferably by gravity) to position 53 while, conversely, a bowl under the finger-lever forcibly raises the outer end of the floating lever F to position 52.

For moving each of the dogs 38 or 39 into the path of the corresponding lifter-bar 44 or 45 respectively, there is provided a positioning lever fulcrumed on a fixed rod 62 or 63 respectively. Each of these dog-positioning levers, for example that one associated with the dog having the arm 38, has three arms, the arms 64 and 66 of this lever, as shown in FIG. 1, diverging from one another and each having a roll at its free end operative, alternatively, to engage the arm 38. The lever corresponding to the dog having the arm 39 also has three arms, the arms 65 and 66 diverging from one another and each having a roll for engagement with the dog 39.

The third arm '68 of the lever, associated with the dog having arm 38, is pivotally connected to the upper end of a link '70 whose lower end is pivotally connected to the corresponding floating lever or determinator F at the midpoint or" the latter, while the third arm 6 of the dog, comprising the arm 3%, is pivotally connected to a link 71 whose upper end is also pivotally connected to the midpoint of the corresponding floating lever F or determinator.

It is understood, of course, that while in MG. 1 only a single power-driven segmental drive gear 20 is shown at the upper part of the view, with its cooperating crankgear 12, shifter lever 28, actuating dog, and dog-positioning lever; and likewise, in the lower part of said view a single segmental drive gear 2 1 and corresponding parts have been shown, in the actual loom there will be such a complete assemblage of parts corresponding to each headle-actuating jack, as well as a corresponding patternchain, pattern-follower, link, determ-inator means and control element for each jack.

If, as shown at the upper portion of FIG. 1, where the jack-lever 1 is so positioned that the corresponding healdframe is down, the long arm 46 of the corresponding control lever is in the up position so that its free end occupies the position in space, indicated by the numeral 50, then, with the pattern-follower or finger-lever 57 resting upon a tube T of the pattern-chain, the midpoint 55 of the floating lever or determinator P will be in idle position, such that the link 70- holds the corresponding threearm lever, as shown in FIG. 1, with both rolls 64 and 66 in neutral position. Thus, the dog 38 is out of the path of the lifting-bar d4 and the shifting lever 28 is in corresponding neutral position so that no rotation of the crankgear 12 will take place and the heald-frame will remain down.

If, however, again with the heald-frame down, fingerlever 57 were lifted by a bowl on the pattern-chain, then the outer end of the floating lever F would be lifted to position 52 and, consequently, its intermediate control point would move to position 54. This change would lift link 7%) and swing the three-arm lever on its fulcrum 62 (anti-clockwise in FIG. '1), with the resultant effect that arm 64 will place the dog or push-rod having the arm 38 in the vertical position to be engaged at its lower end and lifted by the rising lift or servo-bar 44. This would cause the gears 12 and 20' to engage and rotate crank-gear 12 a half-turnthereby actuating jack-lever 1 to the right and lifting the corresponding heald in response to the bowl on the pattern-chain.

As shown at the lower part of FIG. 1, jack-lever 2, when it last lifted its heald-frame (not shown) allowed the free end of its control lever d7 to descend to position -1. This means that when the pattern-chain next brings a tube T under the pattern-follower lever 57, as shown, the corresponding heald will go down since the mid or control point of the floating lever or determinator F will have now moved to the lowest possible position indicated by the numeral 56 and, as a consequence, link 71, as shown, will have swung the corresponding three-arm lever about its fulcrum bar 63 to cause its arm 67 to place the dog or push-rod 39 in vertical position to be engaged by and in due course lifted by the lifting-bar 45. As a consequence, the gears 21, 13 will engage and crank-gear 13 will be rotated 21 half-turn, thereby actuating jack-lever 2 and lowering the corresponding heald-framein response to a tube on the pattern-chain.

FIG. 4 shows diagrammatically the automatic selective action of the floating-levers F when acting in combination with the feeler levers or control elements, the three-armed levers and the pattern-chain finger-levers or pattern followers to control the hinged pushrods or dogs having the arms 38 or 39. In FIG. 4, D is an abbreviation for down, U for up, C for change and M for miss or no-change. Thus, when the heald-frame is down, the inner end of the floating-lever 'F is at St but when the heald-frame is up, the inner end is at 51. When the finger-lever 57 rests on a tube, the outer end of the floating-lever is at 53, but if the finger-lever is resting on a bowl, the outer end of the floating-lever is at '52,.

Each floating-lever, therefore, may assume any one of four possible attitudes or positions, as indicated in FIG. 4. When it is in either diagonal position, the intermediate control point is in the midway vertical position 55, in which case, by means of vertical link 7G or 71, the associated three-arm lever is held in its midway or neutral position in which the push-rod 38, 3? is not engaged by the lifting-bar and the heald therefore dwells with its 10 position unchanged. The servo mechanism is, under these conditions, inoperative as regards that particular jack and heald frame.

When, however, the floating-lever is in either horizontal position, so that the intermediate control point is either at the top position 54 or the bottom position 56 then, as shown in FIG. 1, the corresponding three-arm lever is swung from its neutral position either one way or the other to cause either the top arm 64- (65) or bottom arm 66 (67) to place the push-rod 38 (39) in vertical position where it will be engaged and lifted by the rising liftingbar 44 or 45. Such selectively controlled relay action, as already explained, causes the associated drive-gear 20 and crank-gear 1 2 (or the drive-gear 21 and associated crank-gear 13), as the case may be, to engage and thereby turn the respective crank-gear a half-turn, thereby moving the heald-frame either up or down, respectively, as indicated either by a bowl following a tube, or by a tube following a bowl on the pattern-chain.

When, in the above-described manner, the three-arm lever has been swung about its fulcrum one Way or the other from its midway or neutral position, shown at the upper part of FIG. 1, so as to cause either the arm 64- or the arm as to place the push-rod or dog, having the arm 38, in position to be engaged by the lifter-bar 44 and the latter is then raised by the cam-actuated lever 78 which rises the appropriate distance and then dwells at the top of its upward movement until the gears have completed their engagement, at which time the crank-gear has been rotated a half-turn and has actuated the corresponding jack-lever and its attached heald-frame. During each such period of dwell of the cam-actuated lever 78 and gear engagement and the consequent movement of a jacklever, the associated control element 46 or 47 moves in accordance with the changing position of the heald-frame, i.e. either up or down in consequence of which the inner end of the floating-lever F moves accordingly. This movement, which occurs con-currently with the heald change, causes the three-arm lever to return to its midway or neutral position in readiness for the next automatic selection as the pattern-chain is next notched around.

Such return of the three-arm 'levers to their midway positions during the gear engagement does not prejudice the previous selective positioning of the hinged push-rods or dogs having the arms 38 or 59, respectively, because these are now engaged with and lifted by the corresponding lifting-bar and subject to the Weight of their cam levers 2 8, 2%. To lock a push-rod or dog having the arms 38 or 39, respectively, when in engagement with the corresponding lifting-bar 44 or 45, once the latter has lifted and engaged the dog arm, the top edge of the liftingbar is preferably made convex (FIG. lb), while the lower end of the corresponding push-rod is made concave or hollow-ground to match. The best radius of the convexity is about A of the length of the arm 38 of the dog. The lifting-bar may, however, have its upper or lifting edge fiat or shaped in any other suitable manner with the engaging end of the push-rod shaped to match. This locking of the selected push-rod by the corresponding lifting-bar makes the carrying-out of the jack-changing movement independent of any loom stoppage or current failures as the engagement of the parts 38 (39) and 4-4 (d5) is maintained until the jack movement has been completed.

FIG. 5 shows a modification of the invention in which the automatic selection action is achieved by electro-mechanical means instead of by wholly-mechanical means. In this figure, each finger-lever or pattern-follower 3'), when moving in response to the bowls or tubes of the pattern-chain '60, actuates an electrical switch 82, which has pairs of electrical contacts U-Z and D2. The contacts D-Z are bridged when the finger-lever 37 rests on a tube of the pattern-chain. Alternatively, contacts U-Z are bridged when the finger-lever rests on a bowl of the 1 1 chain. A suitable resilience will be allowed for to insure good electrical contact in both positions.

Each feeler-lever or control element, such as 46 or 47, when moving to indicate a change of the position occupied by the jack-levers and their attached heald-frames, actuates an electrical switch 81, which also has two pairs of electrical contacts, namely U-l and 13-1. The contacts D1 are bridged when the heald-frarne is down. Similarly, contacts U-l are bridged when the heald-frame is up.

Each push-rod or dog (such as the dogs having the arms 38 or 39, respectively), is controlled by an electromagnet or solenoid, such as indicated at 83 and 84. Referring to the upper portion of FIG. 5, so long as the solenoid is not enengized, the spring 42 acts to swing the push-rod or the dog having the arm 38 to the right sufficiently to clear the rising lifting-bar 4.4, and also to return the solenoid plunger 83 to its inert position. When the solenoid is energized, however, it overcomes spring 42 and places the push-rod or dog with its arm 33 in the vertical position where, in due course, it will be engaged and lifted by the lifting-bar '44, with the resultant effect previously described.

The two switches 81 and 82, according to their separate actuation in the manner described, constitute the determinator means, providing four different combinations, analogous to the four diiferent positions of the floatinglever or determinator F of FIGS. 1 and 4, and with equivalent automatic selection. These switches may both be closed in either of two parallel circuit paths, or one only may be closed in each path.

As shown in FIG. 5, a tube on the pattern-chain causes finger-lever 37 to bridge contacts D-Z in pattern switch 3 2, and jack-lever 2, with its heald-frame down, causes feeler-lever or control element 46 to bridge contacts D-l in position switch 81.

In other words, the heald-frame is already down and is to remain down for the ensuing pick, consequently, no change is required. Tracing the connection diagram, it is apparent that the above-stated disposition of switches 81 and 8-2 is such that solenoid 83 is not energized, which is in precise accord with the indicated requirement.

On the other hand, if the finger-lever 37 had been resting on a bowl in the pattern-chain, indicating that the heald-frame had next to be lifted, then contacts U2 in pattern switch $2 would have been bridged, which in combination with the already bridged contacts D-l in position switch 81, would complete the electric circuit and energise solenoid 63. The push-rod or dog having the arm 38 would then be engaged by lifting-bar 44 with the result that the heald-frame would next be lifted, which is in precise accordance with the indicated requirement. Alternatively, if the jack-lever and heald-frame had been in their up position, then contacts U1 in the position switch '81 would have been bridged, and on the assumption of finger-lever 3'7 resting on a tube, as shown in FIG. 5, so that contacts D.'& in pattern box 82 are bridged, then again solenoid 63 would be energised, with the result, in this case, that the heald-frame would be lowered to its down position in accordance with the indicated requirements.

During the mechanical actuation of the jack-levers, the jack feeler-levers or control elements change their positions accordingly, along with the position switches 81. When this occurs, however, the selected push-rods or dogs are already engaged with and locked on their lifting-bars, and the interruption of the solenoid circuits, at this stage, due to such actuation of the switches has no harmful effect on the automatic selection or the reliable operation of the improved dobby as a whole.

As will be readily apparent, hinged hooks arranged to engage a moving knife or griff may be used with similar effect in lieu of the hinged push-rods or dogs and lifting bars shown in the attached drawings.

In order not to overheat the solenoids 83, 84 especially in cases where the loom is stopped during a change, a conventional cut-out switch (not shown) may be provided, operated, for example, by a suitable cam (not shown) synchronized with the shafts 18 and 19, and timed so as to de-enerise the solenoids as soon as the push-rods or dogs having the arms 3% or 39, respectively have become locked by the shifting bars 44, 45, this switch closing again when or just after the pattern chain is stepped forward to determine the next position of pattern switch 32;.

For the purpose of levelling the heald frames, as and when required, three levelling-bars 88, 89 and are provided (see FIGS. 1 and 5). These bars will be supported in any suitable manner and arranged to be moved under control of manually-operated means (not shown) such as two hand-levers mounted on the front dobby frame, preferably within easy reach of the weaver. One such hand-lever actuates the levelling-bar 88, and the other hand-lever actuates the twin levelling-bars 89 and These controls are used only as and when it is desired to bring all the heald-frames to a common level, or thereabouts (for instance to facilitate examination of and/or repairs to the warp yarns) and subsequently to restore the heald-frames to normal operation position and under control of the pattern-chain.

In FIGS. 1 and 5 the levelling-bars 88, 89 and 90 are shown in their inoperative positions which they occupy throughout the looms normal operation. In such inoperative positions, the said levelling-bars permit unrestricted movement of the finger-levers or pattern followers 57, and also of the hinged push-rods or dogs having the arms 33 or 39, respectively.

The selected levelling control bar is put into operation by the weaver only with the loom stopped and at rest with the cranks on back-centre, corresponding to position BC in FIG. 3, in which position of the loom the gears 36, 37 and 13, 21 are safely disposed as shown in FIGS. 1 and 5.

When it is desired, on the one hand, to bring all the heald-frames to their topmost positions, the levelling-bar 88 is raised (throughout its full length) by said manual control so as to lift all the finger-levers or pattern followers 57 as if each was resting on a bowl on the pattern-chain 60. When so raised, bar 88 thus overrides the pattern chain and, upon the turning of the loom over by hand in the forward direction some three-quarters of a revolution of the crankshaft, those heald-frames which were previously down are lifted to their topmost positions, where they join those frames which were already up. To restore the heald-frames to the operating position which they occupied before levelling, and to bring them again under control of the pattern-chain, the loom crankshaft, together with the dobby, is reversed by hand until the slay is returned to its back position, after which the levelling-bar $8 is lowered by said manual means to its inoperative position, thereby allowing the finger-levers 57 to rest on the bowls and tubes of the pattern-chain oh. This simple procedure sufiices to restore the shed formation as it existed prior to starting the top levelling operation, and the loom is ready to continue weaving.

When it is desired, on the other hand, to bring all the heald-frames to their mid-travel, or centre-shed, position, the twin levelling-bars 89 and 90 are moved to the left (FIGS. 1 and 5), preferably by a conventional hand-lever or like means (not shown), such movement being sulficient to ensure that all the hinged push-rods or dogs having the arms 38 or 39 (irrespective of their normal actuation by the floating-levers F) are forcibly displaced to the left into a vertical position in which, as already described, they will be engaged and lifted by the twin lifting bars 44- and 45. Upon turning the loom over by hand in the forward direction to bring the slay from the back to the front (corresponding to half a revolution of the loom crankshaft) all the heald-frames are brought to their midtravel, or centre-shed, position. To restore normal operation, the loom crankshaft, together with the dobby, is re- 13 versed to return the slay to its back position. The levelling-bars 89 and 90 are then returned by hand to their inoperative positions shown in FIGS. 1 and 5, thereby restoring control of the hinged push-rods 3S and 39 to the floating levers F, in readiness for continuation of weaving.

The automatic selective mechanism herein described may be used with corresponding effect and advantage in connection with shuttle-box motions, and also in other situations where a plurality of members are to be moved independently between two end positions in accordance with the serial reading of a pre-arranged pattern.

What I claim is:

1. In a loom of the kind wherein a heald frame is moved up or down by a jack lever, a power-driven shaft which makes one revolution for each cycle of operation of the loom, power-actuated means for rocking the jack comprising a crank and connecting rod, and means which receives power from said shaft for turning the crank a half revolution and then causing it to dwell, a pattern device including a series of pattern indications of two different kinds, said pattern device being pegged for risers and fallers, servo-means operative, at times, to initiate operation of said power-actuated means thereby to turn the crank and rock the jack, a control element movable in time with the jack, and determinator means operative, in response to the concomitant action of a pattern indication and the control element, thereby to activate the servomeans or alternatively to cause it to remain idle during each successive cycle of the loom.

2. In a dobbie for use in a weaving loom of the type wherein, for actuating a heald frame, there is provided a power-driven segment gear operative to engage or disengage a corresponding crank gear which, at each such engagement, turns one-half revolution and then dwells, and wherein the crank gear is so connected to a jack-as to rock the latter in one direction or the other at each successive half revolution of the crank gear thereby lifting or lowering the heald frame, power-actuated shifting means for operatively engaging or disengaging the segmental and crank gears, a pattern device comprising an endless series of pattern indications of two different kinds, respectively, a pattern follower whose response to the pattern device varies in accordance with the kind of pattern indication to which it is presented, in combination, a control element which occupies either of two predetermined positions according to the instant position of the jack, and determinator means responsive concomitantly to the pattern follower and to the control element to determine whether or not said power-actuated shifting means shall function or remain idle.

3. The combination according to claim 2, wherein for actuating the shifting means there is provided servo-means comprising a power-driven, reciprocating part, and a normally idle dog which, when disposed in the path of said reciprocating part, transmits motion of the latter to the shifting means thereby operatively to engage said gears.

4. Apparatus according to claim 3, having means for lifting all of the heald frames to the top position comprising a manually actuatable part operative to lift all of the pattern followers to the position which they would occupy if raised by an indicator of the pattern chain such as calls for the lift of a heald frame whereby, upon turning the loom forward by hand, all of the heald frames previously down will be lifted.

5. The combination according to claim 3, having means for levelling all of the heald frames to mid-position, comprising means for moving all of the servo-motor dogs into operative position whereby, upon turning the loom forwardly by hand to bring the lay of the loom from back to front, all of the heald frames will be placed in midposition.

6. The combination according to claim 1, wherein in response to the concomitant action of the control element and the pattern device the determinator means may assume either of two neutral conditions or either of two operative conditions and wherein, when the determinator means assumes either of its neutral conditions, the servo-mechanism is rendered inoperative so that throughout that pick cycle the jack and its connected heald frame dwell without change of position; and when the determinator means assumes either of its operative conditions the servo-mechanism is made operative to shift the jack and its connected heald frame, the control element which moves in time with the jack being so constructed and arranged that as the jack completes its motion the determinator means is restored to its neutral condition.

7. The combination according to claim 3, wherein the dog is a bell-crank lever having an arm operatively related to the shifting means and a second arm which is movable into and out of the path of the reciprocating part.

8. The combination according to claim 3, wherein for moving the dog from inoperative to operative position there is a mechanically actuated part controlled by the determinator means.

9. A dobbie according to claim 8, further characterized in having means operative to assure the completion of the motion of a jack from one position to the other after it has once been initiated.

10. The combination according to claim 9, wherein for assuring the completion of the motion of a jack from one position to the other after motion has been initiated, the dog and the reciprocating part have interengaging faces operative to keep them in engagement until the motion of the jack has been completed.

11. A loom dobbie according to claim 2, comprising a power-driven cam which makes one revolution for each revolution of the segmental gear, a lifter element which is moved in one direction, at least, by said cam, a normally idle dog operative, when moved to active position, to transmit motion from said lifter element to said gear shifting means, and means actuatable by the determinator means for moving the dog to operative position.

12. Apparatus according to claim 11, wherein the cam for actuating the lifter element is symmetrical with respect to a line connecting the front and back centers of the loom crankshaft whereby the dobbie may be operated in either direction with the same effectiveness.

13. A loom dobbie according to claim 2, wherein the determinator means is a rigid lever, one end of which is pivotally connected to the control element, means connecting the other end of said lever to a pattern follower, which occupies one or another of two predetermined positions in accordance with pattern indications of the two different types, respectively, and means connected to the center point of said determinator lever for determining whether or not said dog shall occupy a neutral or operative position, respectively, depending upon the position in space of the central point of the determinator lever.

14. In a dobbie of the class described for use in a weaving loom having a power-driven shaft and which comprises a jack which is movable back and forth from one predetermined position to another, actuating means operative, at times, to move the jack from one of said positions to the other, a pattern device comprising a plurality of signal elements of two distinct kinds respectively, servo-means operative, at times, to connect said jack-actuating means to a source of power whereby to operate the jack-actuating means so as to shift the jack from one of said positions to the other, and sensing means responsive to a signal element of either of said kinds, in combination, a control element movable from one predetermined position to another in response to motion of the jack, and determinator means responsive concomitantly to the control element and to the sensing means for determining whether or not the servo-means shall function during any given cycle of the power-driven shaft.

15. A dobbie according to claim 14, wherein the determinator means comprises a floating lever, means connecting one end of said lever to the control element, means connecting the opposite end of the lever to the sensing means, and a motion-transmitting part, connected to the midportion of the floating lever and which, in accordance with the position of said midportion of the floating lever, causes the servo-means to function or remain idle, respectively.

16. A dobbie according to claim 15, further characterized in that the end of the floating lever which is connected to the control element may occupy either of two positions according to the position of the control element and that end of the floating lever which is connected to the sensing means may occupy either of two positions according to the kind of signal element engaged at a given time by the sensing means, whereby the floating lever may occupy any one of four positions in two of which the servo-means is idle and in two of which the servo-means is operative.

17. A dobbie according to claim 16, further characterized in that the parts are so constructed and arranged that motion of the jack, from one position to another in response to the actuation of the servo-means, so positions the control element that the floating lever is automatically returned to one or the other of those positions at which the servo-means remains idle as the jack completes its movement.

18. In a loom of the class described which includes a constantly rotating power-driven shaft, a jack which is movable, on signal, between two predetermined positions, means capable of transmitting motion from said shaft thereby to shift said movable jack from one position to the other, pattern means, comprising pattern indications of two different kinds, for determining whether said jack shall be moved, means operative, in response to a given pattern signal, so to activate the motionransmitting means as to shift the jack from one of said positions to the other, and means responsive to the completion of such motion of the jack to determine whether or not the motion-transmitting means shall respond to the next pattern signal.

19. A dobbie for use in a weaving loom of the kind wherein each of a plurality of heald frames is lifted or lowered by the rocking of a corresponding jack and the jacks which actuate alternate healds are arranged in two groups respectively, the jacks of the two groups rocking about spaced parallel axes, each jack of each group being rocked by a crank gear which is turned a half revolution by a corresponding segmental gear, when engaged by the latter, and having a power-actuated shifter associated with each respective segment gear for operatively engaging or disengaging it from the corresponding crank gear, further characterized in that for each jack there is a control element, a pattern device pegged for risers and fallers, a pattern follower, and determinator means responsive to the concomitant action of the control element and pattern device thereby to determine whether or not the power-actuated means shall engage a segmental gear with a corresponding crank gear or allow said crank gear to remain idle.

20. A dobbie according to claim 19, comprising servomeans for actuating the shifter, said servo-means compris ing a dog movable from inoperative to motion-transmitting position and wherein the determinator means comprises a floating lever, one end of which is positioned by the control element and the other end of which is positioned by the pattern follower, and means so connecting the midpoint of said floating lever to the dog that when both ends of said lever are in uppermost or lowermost position, the dog is disposed in operative position and when but one end of said lever is in uppermost position the dog is inoperative.

21. A dobbie for use in a weaving loom of the kind wherein each of a plurality of heald frames is lifted or lowered by the rocking of a corresponding jack and the jacks which actuate alternate heald frames are arranged in two separate groups, the jacks of the respective groups rocking about axes which are parallel but spaced vertically, one above the other, and for actuating each jack there is a constantly rotating, power-driven segment gear operative to engage or disengage a corresponding crank gear which, at each such engagement, turns one-half revolution and then dwells, and wherein each crank gear is so connected to its jack as to rock the latter in one direction or the other at each successive half revolution of the crank gear thereby lifting or lowering the corresponding heald frame, a power-actuated shifter for operatively engaging or disengaging the segmental and crank gears of each pair, respectively, a pattern device for each respective jack, each pattern device comprising an endless series of pattern indications of two different types, respectively, a pattern follower for each series of pattern indications and which occupies two different positions in accordance with the type of indication to which it responds at any instant, a control element corresponding to each jack and which occupies either of two positions according to the instant position of the jack with which it is associated, in combination, motion-transmitting means for determining the operation of the power-actuated means which operatively engages or disengages each segmental gear with its corresponding crank gear respectively, said motion-transmitting means comprising determinator means corresponding to each jack and whose condition depends upon the concomitant action of the control element and the pattern follower corresponding to each respective jack, said determinator means, in accordance with its condition, determining whether or not a given indication of the pattern device shall initiate a change in the position of the corresponding jack-lever.

22. In combination in a loom of the kind wherein each heald frame is moved up or down by a corresponding jack-lever which is required to rock from one of two predetermined positions to another and to dwell or not to dwell in either of said positions as determined by a pattern device while the loom crankshaft makes successive revolutions, and wherein for actuating each jack-lever there is a power-driven driving gear having teeth arranged in a single arcuate segment with an untoothed segment between the ends of the toothed segment and a corresponding driven gear, said latter gear having teeth disposed in diametrically opposite segments, each less than in extent and with untoothed segments in the spaces between the ends of the toothed segments, each driving gear being axially movable thereby to engage its teeth with or to disengage them from the teeth of the driven gear, a crankpin fixed to each of the driven gears, a rod connecting each crankpin to a corresponding jack-lever, the several pairs of gears being arranged in two banks with the crank gears of the respective banks actuating alternate jack-levers, the pattern device comprising a series of signal elements including elements of two different kinds respectively, a pattern follower which occupies either of two positions in accordance with the kind of signal element with which it cooperates at any given cycle, means comprising a solenoid for determining whether or not the driving and driven gears shall be engaged, the terminals of said solenoid being connected into two parallel circuits, a four-pole switch which is operative to close one or the other of said circuits in accordance with the instant position of the pattern follower, and a second four-pole switch which is operative to close one or the other of said circuits in accordance with the instant position of the corresponding jack, the circuits being so arranged that when both switches are closed to complete either circuit the solenoid is energized, and when both switches are closed, but complete different circuits, the solenoid is unenergized.

23. In combination in a loom of the kind wherein each heald frame is moved up or down by a corresponding 17 jacklever which is required to rock from one of two predetermined positions to another and to dwell or not to dwell in either of said positions as determined by a pattern device while the loom crankshaft makes successive revolutions, and wherein for actuating each jack lever there is a pair of segmental gears, one gear of the pair being a power-driven driving gear having teeth arranged in a single arcuate segment with an untoothed segment between the ends of the toothed segment, and the other gear of the pair being a driven gear, said latter gear having teeth disposed in diametrically opposite segments, each less than 180 in extent and with untoothed segments in the spaces between the ends of the toothed segments, each driving gear being axially movable thereby to engage its teeth with or to disengage them from the teeth of the driven gear, a crankpin fixed to each of the driven gears, a rod connecting the crank-pin of each driven gear to a corresponding jack-lever, the several pairs of gears being arranged in two banks with the crank g ars of the respective banks actuating alternate jacklevers, the pattern device comprising a series of signal elements including elements of two different kinds respectively, a control element corresponding to each jacklever and which occupies either of two positions in accordance with the instant position of its jack-lever, and determinator means comprising a floating lever corresponding to each jack-lever, one end of the floating lever being connected to the corresponding control element and the other end of the floating lever occupying one of two positions as determined by the kind of signal element which, in any given cycle, is in operating position, whereby the floating lever may occupy either of four positions in space, and servo-means, so responsive to the instant position of the midpoint of said floating lever, as to engage the driving and driven gears of the corresponding pair or to leave them disengaged.

References Cited in the file of this patent UNITED STATES PATENTS 719,289 Wyman Jan. 27, 1903 1,075,862 Ryon Oct. 14, 1913 1,371,564 Leeming Mar. 15, 1921 2,136,765 Staubli Nov. 15, 1938 2,640,504 Blanchard June 2, 1953 2,687,751 Moir Aug. 31, 1954 2,904,078 Pellis Sept. 15, 1959 

1. IN A LOOM OF THE KIND WHEREIN A HEALD FRAME IS MOVED UP OR DOWN BY A JACK LEVER, A POWER-DRIVEN SHAFT WHICH MAKES ONE REVOLUTION FOR EACH CYCLE OF OPERATION OF THE LOOM, POWER-ACTUATED MEANS FOR ROCKING THE JACK COMPRISING A CRANK AND CONNECTING ROD, AND MEANS WHICH RECEIVES POWER FROM SAID SHAFT FOR TURNING THE CRANK A HALF REVOLUTION AND THEN CAUSING IT TO DWELL, A PATTERN DEVICE INCLUDING A SERIES OF PATTERN INDICATIONS OF TWO DIFFERENT KINDS, SAID PATTERN DEVICE BEING PEGGED FOR RISERS AND FALLERS, SERVO-MEANS OPERATIVE, AT TIMES, TO INITIATE OPERA- 